A power converter, an electric drive system and a method for operating a power converter are disclosed. The power converter has connections for connecting to a direct voltage source and connections for electrical connection to phase lines of the electric drive machine. The power converter is configured to convert a direct voltage from the direct voltage source via a direct voltage intermediate circuit into an alternating voltage in order to drive the drive machine. The power converter includes bridge branches for connecting a high-potential section to a low-potential section. A bridge branch includes two half branches with at least one switching device. A resulting nominal voltage of a half branch is greater than a counter-electromotive peak voltage between two phase lines at the maximum rotational speed of the drive machine. A half branch of a bridge branch includes a series circuit of two or more than two switching devices.
Legal claims defining the scope of protection. Each claim is shown in both the original legal language and a plain English translation.
1. An electric drive system for a rail vehicle comprising: a power converter; and an electric drive machine which is connected to the power converter, wherein the electric drive machine is a permanently-excited drive machine, wherein the power converter has connections for connecting to a direct voltage source and connections for electrical connection to phase lines of the electric drive machine, wherein the power converter is configured to convert a direct voltage from the direct voltage source via a direct voltage intermediate circuit into an alternating voltage in order to drive the electric drive machine, wherein the power converter comprises at least one bridge branch for connecting a high-potential section to a low-potential section, wherein the at least one bridge branch comprises two half branches with at least one switching device in each case, wherein a resulting nominal voltage of at least one half branch is greater than a counter-electromotive peak voltage between two phase lines of the electric drive machine at a maximum rotational speed of a rotor of the electric drive machine, and wherein at least one half branch of the bridge branch comprises a series circuit of at least two switching devices.
The invention relates to an electric drive system for rail vehicles, addressing the need for efficient power conversion and reliable operation of permanently-excited electric drive machines. The system includes a power converter and an electric drive machine, where the drive machine is permanently excited, meaning it does not require external excitation for operation. The power converter connects to a direct voltage source and supplies alternating voltage to the drive machine's phase lines. It converts direct voltage from the source into alternating voltage via a direct voltage intermediate circuit, enabling the drive machine to operate. The power converter features at least one bridge branch that links a high-potential section to a low-potential section. Each bridge branch consists of two half branches, each containing at least one switching device. The nominal voltage of at least one half branch exceeds the counter-electromotive peak voltage between two phase lines of the drive machine at its maximum rotational speed, ensuring reliable operation under high-speed conditions. Additionally, at least one half branch includes a series circuit of two or more switching devices, allowing for higher voltage handling and improved system performance. This design enhances efficiency, reliability, and power handling in rail vehicle electric drive systems.
2. The drive system according to claim 1 , wherein the power converter is designed as an n-level inverter, wherein n is greater than two.
A drive system for electric or hybrid vehicles includes a power converter designed as an n-level inverter, where n is greater than two. The system addresses the need for efficient power conversion in high-voltage applications, particularly in electric propulsion systems. Traditional two-level inverters have limitations in harmonic distortion and voltage step resolution, which can affect motor performance and energy efficiency. The n-level inverter improves upon this by providing multiple voltage levels, reducing harmonic content and enabling smoother voltage transitions. This design enhances power quality, reduces electromagnetic interference, and improves overall system efficiency. The inverter can be configured with any number of levels (n > 2), allowing flexibility in balancing performance, cost, and complexity. The system may also include a controller to manage the inverter's operation, ensuring optimal power delivery to the electric motor. This technology is particularly useful in automotive, industrial, and renewable energy applications where high-power, high-efficiency conversion is required.
3. The drive system according to claim 2 , wherein the power converter is designed as a three-level inverter.
A drive system for electric machines, particularly for industrial or automotive applications, addresses the need for efficient power conversion with reduced harmonic distortion and improved reliability. The system includes a power converter that interfaces between a power source and an electric motor, converting direct current (DC) to alternating current (AC) with controlled voltage and frequency. The power converter is specifically designed as a three-level inverter, which provides multiple voltage levels in the output waveform. This design reduces harmonic content compared to traditional two-level inverters, leading to lower electromagnetic interference and smoother motor operation. The three-level inverter also allows for higher voltage operation with lower switching losses, improving overall system efficiency. Additionally, the inverter's topology may include redundant switching paths to enhance fault tolerance and reliability. The drive system may further incorporate control algorithms to optimize power delivery based on load conditions, ensuring stable and efficient motor performance across varying operational demands. This configuration is particularly beneficial in high-power applications where minimizing energy loss and maintaining motor longevity are critical.
4. The drive system according to claim 2 , wherein the series circuit of at least one half branch comprises three switching devices.
A drive system for electric motors or other loads includes a power converter with a series circuit of at least one half-branch, where each half-branch contains three switching devices. These switching devices are semiconductor-based and arranged to control the flow of electrical power to the load. The system is designed to improve efficiency, reliability, or performance in power conversion applications, particularly in variable-speed drives or motor control systems. The three switching devices in each half-branch may be configured to handle different voltage or current levels, allowing for flexible power distribution and fault tolerance. This configuration can reduce switching losses, enhance thermal management, or provide redundancy in case of device failure. The drive system may also include control circuitry to coordinate the switching devices, ensuring stable and precise power delivery to the load. The use of three switching devices in a half-branch distinguishes this design from conventional two-device configurations, offering potential advantages in power density, efficiency, or operational robustness. The system is applicable in industrial automation, renewable energy, electric vehicles, or other high-power applications where reliable and efficient power conversion is required.
5. The drive system according to claim 2 , wherein a direct voltage intermediate circuit comprises a series circuit of at least two capacitive elements.
The invention relates to a drive system for electric or hybrid vehicles, focusing on improving the efficiency and reliability of power conversion in the intermediate circuit. The system addresses the problem of voltage fluctuations and energy storage limitations in traditional drive systems, which can lead to reduced performance and increased wear on components. The intermediate circuit in the drive system includes a series arrangement of at least two capacitive elements, such as capacitors, to enhance voltage stability and energy storage capacity. This configuration allows for better filtering of voltage ripples and improved handling of transient power demands, particularly during acceleration or regenerative braking. The capacitive elements are designed to work in conjunction with other components, such as inverters and power converters, to ensure smooth power delivery to the electric motor. By distributing the capacitive load across multiple elements, the system reduces stress on individual components, extending their lifespan and improving overall system reliability. The invention is particularly useful in high-power applications where maintaining stable voltage levels is critical for optimal performance.
6. The drive system according to claim 4 , wherein a direct voltage intermediate circuit comprises a series circuit of at least two capacitive elements.
The invention relates to drive systems, specifically those involving direct voltage intermediate circuits used in power conversion applications. The problem addressed is improving the performance and reliability of such circuits, particularly in handling voltage fluctuations and ensuring stable power delivery. The drive system includes a direct voltage intermediate circuit that functions as an energy storage and smoothing component between a power source and a load, such as an electric motor. The intermediate circuit is designed with a series arrangement of at least two capacitive elements, which enhances voltage stability and reduces ripple. This configuration allows for better distribution of voltage stress across the capacitive elements, improving durability and efficiency. The series connection also provides redundancy, ensuring continued operation even if one capacitive element fails. This design is particularly useful in high-power or high-voltage applications where voltage fluctuations can degrade performance or cause system failures. The use of multiple capacitive elements in series helps maintain consistent voltage levels, reducing stress on downstream components and improving overall system reliability.
7. The drive system according to claim 5 , wherein at least one capacitor connection section for connecting two capacitive elements of the series circuit in the direct voltage intermediate circuit is electrically connected in each case to a switching device connection section for connecting two switching devices of the half branch.
A drive system for power conversion includes a direct voltage intermediate circuit with a series circuit of capacitive elements and a power converter with multiple half branches. Each half branch contains switching devices for converting direct voltage to alternating voltage. The system addresses the need for efficient power conversion with reliable voltage balancing in the intermediate circuit. The invention provides a capacitor connection section that links two capacitive elements in the series circuit, ensuring stable voltage distribution. This connection is electrically coupled to a switching device connection section that links two switching devices in the half branch, enabling coordinated control of power flow. The design improves system reliability by maintaining balanced voltages across the capacitive elements while facilitating precise switching operations in the power converter. The system is particularly useful in applications requiring high-power conversion with minimal voltage fluctuations, such as industrial motor drives or renewable energy integration. The integration of the capacitor and switching device connections enhances overall system efficiency and reduces the risk of voltage imbalances that could lead to component stress or failure.
8. The drive system according to claim 6 , wherein at least one capacitor connection section for connecting two capacitive elements of the series circuit in the direct voltage intermediate circuit is electrically connected in each case to a switching device connection section for connecting two switching devices of the half branch.
A drive system for power conversion includes a direct voltage intermediate circuit with a series circuit of capacitive elements and a power converter having multiple half-branches. Each half-branch contains two switching devices connected in series. The system addresses the challenge of balancing voltage distribution and improving reliability in high-power applications. The invention provides a capacitor connection section that electrically connects two capacitive elements in the intermediate circuit. This connection is linked to a switching device connection section that connects two switching devices in a half-branch. The configuration ensures balanced voltage distribution across the capacitive elements and switching devices, reducing stress and enhancing system stability. The design is particularly useful in high-voltage direct current (HVDC) and variable frequency drive (VFD) applications where efficient power conversion and reliability are critical. The system may include additional features such as redundant connections or protective mechanisms to further improve performance and fault tolerance. The invention optimizes power flow and minimizes energy losses while maintaining operational safety.
9. The drive system according to claim 7 , wherein the at least one capacitor connection section is connected to a first switching device connection section in a first of the two half branches which connects two switching devices having two sequential ordinal numbers, and wherein the at least one capacitor connection section is also connected to a second switching device connection section in a second of the two half branches which connects two switching devices having same ordinal numbers.
This invention relates to a drive system for power conversion, specifically addressing the challenge of efficiently connecting capacitors in a multi-level inverter topology. The system includes a plurality of switching devices arranged in two half branches, each half branch containing multiple switching devices with sequential ordinal numbers. The capacitor connection section is linked to a first switching device connection section in one half branch, which connects two switching devices with sequential ordinal numbers. Additionally, the capacitor connection section is connected to a second switching device connection section in the other half branch, which connects two switching devices with the same ordinal numbers. This configuration ensures balanced voltage distribution across the capacitors and improves the system's power conversion efficiency. The switching devices are controlled to selectively connect and disconnect the capacitors, enabling multi-level voltage output. The system is particularly useful in applications requiring high-power, high-efficiency power conversion, such as industrial motor drives and renewable energy systems. The described arrangement optimizes capacitor utilization and reduces voltage stress on the switching devices, enhancing overall system reliability.
10. The drive system according to claim 8 , wherein the at least one capacitor connection section is connected to a first switching device connection section in a first of the two half branches which connects two switching devices having two sequential ordinal numbers, and wherein the at least one capacitor connection section is also connected to a second switching device connection section in a second of the two half branches which connects two switching devices having same ordinal numbers.
This invention relates to a drive system for power conversion, specifically addressing the challenge of efficiently connecting capacitors in a multi-level inverter topology to improve voltage balancing and system performance. The system includes a plurality of switching devices arranged in two half branches, each half branch containing multiple switching devices with sequential ordinal numbers. The capacitor connection section is linked to a first switching device connection section in one half branch, which connects two switching devices with consecutive ordinal numbers. Additionally, the capacitor connection section is connected to a second switching device connection section in the other half branch, which connects two switching devices sharing the same ordinal number. This configuration ensures balanced voltage distribution across the capacitors, enhancing stability and efficiency in power conversion applications. The switching devices are controlled to manage energy flow, and the capacitor connections facilitate smooth voltage transitions between different levels, reducing harmonic distortion and improving overall system reliability. The system is particularly useful in high-power industrial drives and renewable energy integration, where precise voltage control and energy efficiency are critical.
11. The drive system according to claim 7 , wherein the electrical connection comprises at least one diode and/or at least one connection switching device.
This invention relates to a drive system for electric or hybrid vehicles, focusing on improving energy efficiency and power management during regenerative braking. The system includes a drive unit with an electric motor and a power converter, along with a control unit that manages energy flow between the motor, a battery, and an auxiliary power source. The key innovation involves an electrical connection that selectively routes energy during regenerative braking, allowing excess energy to be stored or distributed efficiently. This connection includes at least one diode and/or at least one switching device to control the flow of electrical current, ensuring proper direction and preventing backflow. The diode acts as a one-way conductor, while the switching device dynamically adjusts connections based on operational conditions. The system optimizes energy recovery by directing power to the battery or auxiliary systems, reducing energy waste and improving overall efficiency. The control unit monitors system parameters to activate or deactivate the connection as needed, ensuring safe and effective operation. This design enhances regenerative braking performance, extends battery life, and improves vehicle energy management.
12. The drive system according to claim 8 , wherein the electrical connection comprises at least one diode and/or at least one connection switching device.
This invention relates to a drive system for electric or hybrid vehicles, focusing on improving energy efficiency and power management during regenerative braking. The system addresses the challenge of efficiently recovering and storing energy generated during braking, which is otherwise lost as heat in conventional systems. The drive system includes an electric motor, a power converter, and an energy storage device, such as a battery or capacitor. The power converter regulates the flow of electrical energy between the motor and the storage device, ensuring optimal energy recovery during braking and controlled power delivery during acceleration. The system also incorporates an electrical connection that includes at least one diode and/or at least one connection switching device. The diode ensures unidirectional current flow, preventing backflow of energy when not needed, while the switching device dynamically controls the connection between components, allowing for selective activation or deactivation of energy recovery pathways. This configuration enhances system efficiency by minimizing energy losses and improving responsiveness during regenerative braking. The switching device may be a relay, transistor, or other controllable switch, enabling precise control over energy flow. The diode and switching device work together to ensure safe and efficient operation, reducing wear on components and extending the lifespan of the drive system. The overall system optimizes energy usage, reduces reliance on fossil fuels, and enhances vehicle performance.
13. The drive system according to claim 1 , wherein the sum of the nominal voltages of the at least one switching device in one half branch is higher than a counter-electromotive peak voltage between two phase lines of the electric drive machine at the maximum rotational speed of the rotor of the electric drive machine.
This invention relates to a drive system for an electric drive machine, specifically addressing the issue of voltage handling in power electronic converters. The system includes at least one switching device in each half branch of a converter circuit, where the sum of the nominal voltages of the switching devices in one half branch exceeds the counter-electromotive peak voltage generated between two phase lines of the electric drive machine at its maximum rotor speed. This ensures that the switching devices can withstand the highest voltage spikes produced by the machine during operation, preventing damage and improving reliability. The converter circuit may be configured as a multi-level topology, such as a neutral-point-clamped (NPC) or flying capacitor converter, to further enhance voltage distribution and reduce stress on individual components. The system is particularly useful in high-power applications where voltage transients and electromagnetic interference are significant concerns. By selecting switching devices with sufficient voltage ratings, the drive system ensures safe and efficient operation across varying load conditions and speeds.
14. The drive system according to claim 1 , wherein a switching element of the at least one switching device is designed as a silicon carbide switching element, or a gallium arsenide switching element, or as a gallium nitride switching element, or as a diamond switching element, or as an aluminum nitride switching element.
This invention relates to drive systems incorporating advanced semiconductor switching elements for improved performance. Traditional drive systems often use silicon-based switching devices, which have limitations in terms of efficiency, switching speed, and thermal management, particularly in high-power or high-frequency applications. The invention addresses these limitations by employing switching elements made from wide-bandgap semiconductor materials, including silicon carbide (SiC), gallium arsenide (GaAs), gallium nitride (GaN), diamond, or aluminum nitride (AlN). These materials offer superior electrical properties, such as higher breakdown voltages, lower on-resistance, and faster switching speeds compared to silicon, enabling more efficient and compact drive systems. The switching elements are integrated into at least one switching device within the drive system, allowing for enhanced power conversion, reduced energy losses, and improved thermal performance. The use of these advanced materials extends the operational range of the drive system, making it suitable for demanding applications in industries such as automotive, aerospace, and renewable energy. The invention focuses on leveraging the unique characteristics of wide-bandgap semiconductors to overcome the limitations of conventional silicon-based switching devices, resulting in more reliable and high-performance drive systems.
15. The drive system according to claim 13 , wherein a switching element of the at least one switching device is designed as a silicon carbide switching element, or a gallium arsenide switching element, or as a gallium nitride switching element, or as a diamond switching element, or as an aluminum nitride switching element.
The invention relates to a drive system for electric motors, particularly for high-performance applications where efficiency and power density are critical. Traditional drive systems often use silicon-based switching elements, which have limitations in terms of switching speed, thermal performance, and efficiency at high voltages and frequencies. This invention addresses these limitations by incorporating advanced wide-bandgap semiconductor materials in the switching devices of the drive system. The drive system includes at least one switching device, which is a key component for controlling the flow of electrical power to the motor. The switching element within this device is made from a wide-bandgap material such as silicon carbide, gallium arsenide, gallium nitride, diamond, or aluminum nitride. These materials offer superior electrical and thermal properties compared to silicon, enabling faster switching speeds, higher voltage handling capabilities, and reduced power losses. This results in improved overall system efficiency, reduced heat generation, and enhanced reliability, making the drive system suitable for demanding applications such as electric vehicles, industrial machinery, and renewable energy systems. The use of these advanced materials allows the drive system to operate at higher frequencies and voltages while maintaining stability and performance.
16. The drive system according to claim 1 , wherein a freewheeling diode of the at least one switching device is designed as a silicon carbide diode, or a gallium arsenide diode, or as a gallium nitride diode, or as a diamond diode, or as an aluminum nitride diode.
The invention relates to a drive system for electric motors, particularly focusing on improving the performance and efficiency of power electronics used in such systems. Traditional drive systems often suffer from inefficiencies and limitations in switching devices, particularly in their freewheeling diodes, which can lead to energy losses and reduced system reliability. The invention addresses this by incorporating advanced semiconductor materials in the freewheeling diodes of the switching devices within the drive system. These diodes are designed using silicon carbide, gallium arsenide, gallium nitride, diamond, or aluminum nitride, which offer superior electrical properties compared to conventional silicon-based diodes. The use of these materials enables higher switching speeds, lower conduction losses, and improved thermal performance, resulting in a more efficient and reliable drive system. The switching devices, which may include transistors or other power semiconductor components, benefit from these high-performance diodes by reducing energy dissipation and enhancing overall system efficiency. This innovation is particularly valuable in applications requiring high power density, such as electric vehicles, industrial machinery, and renewable energy systems. The advanced diode materials also contribute to longer operational lifetimes and reduced maintenance costs.
17. The drive system according to claim 13 , wherein a freewheeling diode of the at least one switching device is designed as a silicon carbide diode, or a gallium arsenide diode, or as a gallium nitride diode, or as a diamond diode, or as an aluminum nitride diode.
The invention relates to a drive system for electric motors, particularly focusing on improving the performance and efficiency of power conversion in motor drives. Traditional drive systems often suffer from losses and inefficiencies due to the limitations of conventional semiconductor materials in switching devices, especially in freewheeling diodes. These diodes are critical for handling reverse currents and protecting the system during switching transitions, but their performance is constrained by the properties of traditional silicon-based diodes, such as higher forward voltage drops and slower switching speeds. The invention addresses these issues by incorporating advanced semiconductor materials in the freewheeling diodes of the switching devices within the drive system. Specifically, the diodes are designed using silicon carbide, gallium arsenide, gallium nitride, diamond, or aluminum nitride. These materials offer superior electrical and thermal properties compared to silicon, including lower forward voltage drops, higher switching speeds, and better thermal conductivity. This results in reduced power losses, improved efficiency, and enhanced reliability of the drive system. The use of these advanced materials enables the drive system to operate at higher frequencies and under more demanding conditions while maintaining stability and performance. The invention is particularly beneficial in applications requiring high power density, such as industrial motor drives, electric vehicles, and renewable energy systems.
18. An electric drive system for a rail vehicle comprising: a power converter; and an electric drive machine which is connected to the power converter, wherein the electric drive machine is a permanently-excited drive machine, wherein the power converter has connections for connecting to a direct voltage source and connections for electrical connection to phase lines of the electric drive machine, wherein the power converter is configured to convert a direct voltage from the direct voltage source via a direct voltage intermediate circuit into an alternating voltage in order to drive the electric drive machine, wherein the power converter comprises at least one bridge branch for connecting a high-potential section to a low-potential section, wherein the at least one bridge branch comprises two half branches with at least one switching device in each case, wherein a resulting nominal voltage of at least one half branch is greater than a counter-electromotive peak voltage between two phase lines of the electric drive machine at a maximum rotational speed of a rotor of the electric drive machine, wherein at least one half branch of the at least one bridge branch comprises precisely one switching device, and wherein a switching element of the switching device is designed as a gallium arsenide switching element, or as a gallium nitride switching element, or as a diamond switching element, or as an aluminum nitride switching element.
This invention relates to an electric drive system for rail vehicles, addressing the need for efficient and reliable power conversion in electric propulsion systems. The system includes a power converter and a permanently-excited electric drive machine connected to it. The power converter is designed to convert direct voltage from a direct voltage source into alternating voltage via a direct voltage intermediate circuit to drive the electric drive machine. The converter features at least one bridge branch connecting a high-potential section to a low-potential section, with each branch comprising two half branches, each containing at least one switching device. The nominal voltage of at least one half branch exceeds the counter-electromotive peak voltage between two phase lines of the electric drive machine at its maximum rotational speed. Notably, at least one half branch includes precisely one switching device, and the switching element within this device is made from gallium arsenide, gallium nitride, diamond, or aluminum nitride. These materials enable high-frequency switching, improving efficiency and reducing size and weight, which is critical for rail vehicle applications. The design ensures robust operation under high-speed conditions while maintaining compatibility with the drive machine's voltage requirements.
19. The electric drive system according to claim 18 , wherein the permanently-excited drive machine is a permanently-excited synchronous machine.
The invention relates to electric drive systems, specifically those incorporating a permanently-excited drive machine. The system addresses the need for efficient and reliable electric propulsion, particularly in applications requiring high performance and durability. The drive system includes a permanently-excited drive machine, which is a type of electric motor that uses permanent magnets to generate a magnetic field, eliminating the need for external excitation. This design enhances efficiency, reduces maintenance, and improves reliability compared to traditional excitation methods. The system also features a control unit that regulates the drive machine's operation, ensuring optimal performance under varying load conditions. Additionally, the drive machine is configured to operate in both motoring and generating modes, allowing for energy recovery during braking or deceleration. The use of a permanently-excited synchronous machine further improves the system's efficiency and responsiveness, making it suitable for applications such as electric vehicles, industrial machinery, and renewable energy systems. The invention focuses on integrating these components into a cohesive system that maximizes energy efficiency and operational reliability.
20. A method for operating a drive system according to claim 1 , wherein switching times of the at least one switching device may be set as a function of a desired temporal course of a current, which is provided the by power converter at connections for electrical connection to the phase lines of the electric drive machine.
The invention relates to a method for operating a drive system, specifically focusing on controlling the switching times of power electronic devices in a power converter to regulate the current supplied to an electric drive machine. The method addresses the challenge of precisely controlling the current waveform delivered to the electric drive machine, which is essential for efficient and stable operation of the drive system. The method involves adjusting the switching times of at least one switching device within the power converter based on a predefined desired temporal current profile. This allows the power converter to generate a current waveform that matches the desired characteristics, such as amplitude, phase, and harmonic content, at the connections to the phase lines of the electric drive machine. By dynamically setting the switching times in response to the desired current profile, the method ensures that the electric drive machine receives the optimal current for its operation, improving performance and energy efficiency. The switching devices in the power converter are controlled to switch on and off at specific times to shape the output current according to the desired profile. This control can be applied to multiple switching devices, allowing for fine-tuned current regulation across all phases of the electric drive machine. The method may also include feedback mechanisms to adjust the switching times in real-time, compensating for variations in load conditions or system parameters. Overall, the invention provides a technique for precise current control in electric drive systems, enhancing their reliability and efficiency by dynamically adjusting the switching times of power electronic devices based on a predefined current profile.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
September 25, 2020
February 15, 2022
Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.